U.S. patent application number 12/862762 was filed with the patent office on 2011-03-17 for method for improving motion blur and contour shadow of display and display thereof.
This patent application is currently assigned to CHIMEI INNOLUX CORPORATION. Invention is credited to Kai-Chieh Chan, Eddy Giing-Lii Chen, Sz-Hsiao Chen, Tien-Feng Chiang, Sheng-Tien Cho, Kuo-Feng Li.
Application Number | 20110063320 12/862762 |
Document ID | / |
Family ID | 43730083 |
Filed Date | 2011-03-17 |
United States Patent
Application |
20110063320 |
Kind Code |
A1 |
Chen; Eddy Giing-Lii ; et
al. |
March 17, 2011 |
METHOD FOR IMPROVING MOTION BLUR AND CONTOUR SHADOW OF DISPLAY AND
DISPLAY THEREOF
Abstract
A method for improving motion blur and contour shadow of a
display displaying images having a number of frames includes
transforming a second average gray scale into a third average gray
scale when a first average gray scale for displaying a first frame
is unequal to the second average gray scale for displaying a second
frame. A luminance corresponding to the second frame is generated
according to the third average gray scale and at least one
luminance query table. The third average gray scale is greater than
the first average gray scale and the second average gray scale or
less than the first average gray scale and the second average gray
scale.
Inventors: |
Chen; Eddy Giing-Lii;
(Miao-Li County, TW) ; Li; Kuo-Feng; (Miao-Li
County, TW) ; Cho; Sheng-Tien; (Miao-Li County,
TW) ; Chiang; Tien-Feng; (Miao-Li County, TW)
; Chan; Kai-Chieh; (Miao-Li County, TW) ; Chen;
Sz-Hsiao; (Miao-Li County, TW) |
Assignee: |
CHIMEI INNOLUX CORPORATION
Miao-Li County
TW
|
Family ID: |
43730083 |
Appl. No.: |
12/862762 |
Filed: |
August 25, 2010 |
Current U.S.
Class: |
345/589 |
Current CPC
Class: |
G09G 2320/0261 20130101;
G09G 2310/063 20130101; G09G 3/20 20130101; G09G 2340/16
20130101 |
Class at
Publication: |
345/589 |
International
Class: |
G09G 5/02 20060101
G09G005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 16, 2009 |
CN |
200910307093.1 |
Claims
1. A method for improving motion blur and contour shadow of a
display, the display displaying images having a plurality of
frames; the method comprising: transforming a second average gray
scale into a third average gray scale when a first average gray
scale for displaying a first frame unequal to the second average
gray scale for displaying a second frame; and generating a
luminance corresponding to the second frame according to the third
average gray scale and at least one luminance query table, wherein
the third average gray scale is greater than the first average gray
scale and the second average gray scale or less than the first
average gray scale and the second average gray scale.
2. The method as claimed in claim 1, further comprising separating
a motion picture response function corresponding to a gray scale
into a first motion picture response function and a second motion
picture response function on a display panel of the display.
3. The method as claimed in claim 2, further comprising storing the
first motion picture response function and the second motion
picture response function corresponding to gray scales in at least
one luminance query table.
4. The method as claimed in claim 2, wherein the step of generating
a luminance corresponding to the second frame according to the
third average gray scale and at least one luminance query table
comprises looking up the luminance query tables through the third
average gray scale to generate a third motion picture response
function and fourth motion picture response function corresponding
to the third average gray scale.
5. The method as claimed in claim 4, wherein the step of generating
a luminance corresponding to the second frame according to the
third average gray scale and at least one luminance query table
further comprises generating the first frame and the second frame
respectively corresponding to the third motion picture response
function and the fourth motion picture response function.
6. The method as claimed in claim 1, wherein when the third average
gray scale is greater than the first average gray scale and the
second average gray scale, the first average gray scale is less
than the second average gray scale, and a gray scale difference
between the third average gray scale and the second average gray
scale is greater than a critical gray scale difference.
7. The method as claimed in claim 1, wherein when the third average
gray scale is less than the first average gray scale and the second
average gray scale, the first average gray scale is greater than
the second average gray scale, and a gray scale difference between
the third average gray scale and the second average gray scale is
less than a critical gray scale difference.
8. A display, comprising: a display panel displaying images having
a plurality of frames; and a timing controller electrically
connected to the display panel, the timing controller comprising: a
frame memory for receiving and temporarily storing a first frame,
the first frame corresponding to a first average gray scale; a gray
scale curve amending module electrically connected to the frame
memory and receiving a second frame, the second frame corresponding
to a second average gray scale and being received later than the
first frame; a first luminance query table electrically connected
to the display panel and the gray scale curve amending module; and
a second luminance query table electrically connected to the
display panel, the frame memory, and the gray scale curve amending
module, wherein when the first gray scale is unequal with second
gray scale, the gray scale curve amending module processes and
transforms the second gray scale into a third average gray scale,
the first luminance query table outputs a first sub-frame image to
the display panel according to the third average gray scale, the
second luminance query table outputs a second first sub-frame image
to the display panel according to the second average gray scale,
the display panel displays the second frame according to the first
sub-frame and the second sub-frame, and the third average gray
scale is greater than the first average gray scale and the second
average gray scale or less than the first average gray scale and
the second average gray scale.
9. The display as claimed in claim 8, wherein the display panel
displays an image having a plurality of gray scales, and each
motion picture response function corresponding to each gray scale
is separated into a first motion picture response function and a
second motion picture response function on a display panel.
10. The display as claimed in claim 9, wherein the first motion
picture response function is stored in the first luminance query
table, and the second motion picture response function is stored in
the second luminance query table.
11. The display as claimed in claim 8, wherein when the third
average gray scale is greater than the first average gray scale and
the second average gray scale, the first average gray scale is less
than the second average gray scale, and a gray scale difference
between the third average gray scale and the second average gray
scale is greater than a critical gray scale difference.
12. The display as claimed in claim 8, when the third average gray
scale is less than the first average gray scale and the second
average gray scale, the first average gray scale is greater than
the second average gray scale, and a gray scale difference between
the third average gray scale and the second average gray scale is
less than a critical gray scale difference.
13. The display as claimed in claim 8, further comprising a signal
generator electrically connected to the display panel, wherein the
signal generator generates various control signals and transmits
the control signals to the display panel.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure generally relates to displays, and
particularly, to a method for improving motion blur and contour
shadow of a display and display thereof.
[0003] 2. Description of the Related Art
[0004] Display panels are often are driven by using a hold-type
drive method, which may cause motion blur, reducing dynamic image
quality of the display panels. Referring to FIG. 9, the solid line
represents an actual luminance curve of the general display panels
using the hold-type drive method, and the broken line represents a
viewing luminance curve of the conventional display panels using
the hold-type drive method. The frame rate can be set to be 60 Hz;
however, the display panels generate motion blur due to the viewing
luminance values superimposing with the actual luminance values
shown on the solid line.
[0005] A pulse-type drive method is often used on the display
panels to solve the motion blur. Referring to FIG. 10, the solid
line represents an actual luminance curve of the conventional
display panels using the pulse-type drive method, and the broken
line represents a viewing luminance value of the display panels
using the pulse-type drive method. The frame rate can be still set
to be 60 Hz; the average luminance values viewed by the user are
close to the actual luminance values of the display panels, thus
the display panels do not result in motion blur.
[0006] The general pulse-type driver method mainly uses black frame
insertion technology. A single frame can be separated into two or
more consecutive and adjacent sub-frames by using the black frame
insertion technology, in which the later sub-frame is a black
frame. Also referring to FIG. 11, F(n), F(n+1), and F(n+2)
represent three consecutive frame, among them, each frame
corresponds to two sub-frames. For example, frame F(n) corresponds
to sub-frames F(n)_1 and F(n)_2, frame F(n+1) corresponds to
sub-frames F(n+1)_1 and F(n+1)_2, and frame F(n+2) corresponds to
sub-frames F(n+2)_1 and F(n+2)_2, among them, F(n)_2, F(n+1)_2, and
F(n+2)_2 are the black sub-frames in the black frame insertion
technology.
[0007] FIG. 12 shows a schematic view illustrating luminance of all
the frames and the sub-frames shown in the FIG. 11. Provided that
the frame rates of the frames F(n), F(n+1), and F(n+2) are set as
60 Hz, then the frame rates of the sub-frames F(n)_1, F(n)_2,
F(n+1)_1, F(n+1)_2, F(n+2)_1 and F(n+2)_2 are 120 Hz. The black
sub-frames F(n)_2, F(n+1)_2, and F(n+2)_2 respectively have low
luminance in their corresponding frames F(n), F(n+1), and F(n+2),
so that each black sub-frame is inserted between two bright
sub-frames. Thus, the display panel can display images with double
frame rate and alternately dark and bright sub-frames, resulting in
elimination of motion blur.
[0008] However, since the bright sub-frame and the black sub-frame
as a single frame are displayed at the same time, there is an
obvious luminance difference, namely flicker, on the screen. Thus,
even though motion blur is eliminated, image quality is reduced due
to flicker phenomenon. Furthermore, the average luminance of the
single frames is still reduced due to the insertion of the black
sub-frames.
[0009] Therefore, there is room for improvement within the art.
SUMMARY OF THE DISCLOSURE
[0010] An embodiment of the disclosure provides a method for
improving motion blur and contour shadow of a display, and the
method includes the following steps. Transforming a second average
gray scale into a third average gray scale when a first average
gray scale for displaying a first frame unequal to the second
average gray scale for displaying a second frame. Generating a
luminance corresponding to the second frame according to the third
average gray scale and at least one luminance query table. The
third average gray scale is greater than the first average gray
scale and the second average gray scale or less than the first
average gray scale and the second average gray scale.
[0011] An embodiment of the disclosure provides a display for
executing a method for improving motion and contour shadow, and the
display includes a display panel for displaying various frames and
images and a timing controller electrically connected to the
display panel. The timing controller a frame memory for receiving
and temporarily storing a first frame, a gray scale curve amending
module electrically connected to the frame memory and receiving a
second frame, a first luminance query table electrically connected
to the display panel and the gray scale curve amending module, and
a second luminance query table electrically connected to the
display panel, the frame memory, and the gray scale curve amending
module. The first frame corresponds to a first average gray scale
and the second frame corresponds to a second average gray scale and
is received later than the first frame. When the first gray scale
is unequal with second gray scale, the gray scale curve amending
module processes and transforms the second gray scale into a third
average gray scale, the first luminance query table outputs a first
sub-frame image to the display panel according to the third average
gray scale, the second luminance query table outputs a second first
sub-frame image to the display panel according to the second
average gray scale. The display panel displays the second frame
according to the first sub-frame and the second sub-frame. The
third average gray scale is greater than the first average gray
scale and the second average gray scale is less than the first
average gray scale and the second average gray scale.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Many aspects of a method for improving motion blur and
contour shadow of a display and display thereof can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the exemplary method for improving motion blur and contour shadow
of a display and display thereof. Moreover, in the drawings, like
reference numerals designate corresponding parts throughout the
several views. Wherever possible, the same reference numbers are
used throughout the drawings to refer to the same or like elements
of an embodiment.
[0013] FIG. 1 is a schematic view illustrating frames F(n) and
F(n+1) respectively generating two sub-frames Fn_1, Fn_2, and
Fn+1_1, Fn+1_2, according to an exemplary embodiment of the
disclosure.
[0014] FIG. 2 is a schematic view illustrating for separating a
gamma curve f(g) with average luminance into a first gamma cure
f1(g) and a second gamma cure f2(g) according to a predetermined
gray scale x.
[0015] FIG. 3 is a block diagram of a display used for improving
motion blur, according to an exemplary embodiment of the
disclosure.
[0016] FIGS. 4, 5, 6, and 7 are principle schematic views
illustrating improvement of motion blur using a gray scale curve
amending module shown in FIG. 3.
[0017] FIG. 8 is a flowchart illustrating a method for improving
motion blur and contour shadow of a display according to an
exemplary embodiment of the disclosure.
[0018] FIG. 9 is a schematic view illustrating a relationship
between time (X-axis) and corresponding luminance values (Y-axis)
of a conventional display panel using holding-type method.
[0019] FIG. 10 is a schematic view illustrating a relationship
between time (X-axis) and corresponding luminance values (Y-axis)
of the conventional display panel using pulse-type method.
[0020] FIG. 11 is a schematic view showing a single frame
generating two adjacent sub-frames using black frame insertion
technology.
[0021] FIG. 12 is a schematic view illustrating luminance of all
the frames and the sub-frames shown in FIG. 11.
DETAILED DESCRIPTION
[0022] Gamma curve is a relation function used for illustrating a
relationship between luminance and corresponding gray scales of a
display image, namely, a motion picture response function.
Referring to FIGS. 1 and 2, a gamma curve f(g) is divided into a
first gamma cure f1(g) and a second gamma cure f2(g) according to a
predetermined gray scale x, and frames F(n) and F(n+1) respectively
generate two sub-frames Fn_1, Fn_2, and Fn+1_1, Fn+1_2. The
luminance of the frames F(n) and F(n+1) is displayed based on the
gamma curve f(g), the luminance of the sub-frames Fn_1 and Fn+1_is
displayed based on the first gamma curve f1(g), and the luminance
of the sub-frames Fn_2 and Fn+1_2 is displayed based on the second
gamma curve f2(g).
[0023] In detail, the sub-frame Fn_1 and Fn+1_1 correspond to the
output luminance shown on the gamma curve f1(g), and the sub-frame
Fn_2 and Fn+2_2 correspond to the output luminance shown on the
gamma curve f2(g). When the gray scale of the display image is less
than the predetermined gray scale x, the luminance of the first
gamma curve f1(g) is greater than the luminance of the second gamma
curve f2(g), and the first gamma curve f1(g) crosses the second
gamma curve f2(g) at the predetermined gray scale x. When the gray
scale of the display image is beyond the predetermined gray scale
x, the luminance of the first gamma curve f1(g) is less than the
luminance of the second gamma curve f2(g). Thus the gamma curves
f1(g) and f2(g) can be used to represent the luminance of the
single frame, and still maintain the average luminance f(g) of the
single frame. Motion blur range G, as shown in FIG. 2, represents a
considerable change in luminance associated with a little change in
the gray scales, resulting in generating motion blur. When the
length of the motion blur range AG is smaller, namely, the slope of
the gamma curves f1(g) and f2(g) in the motion blur range AG is
greater, then the motion blur is more inconspicuous.
[0024] FIG. 3 shows an exemplary embodiment of a display 100 for
processing a method for improving motion blur and contour shadow of
a display and display. The display 100 includes a timing controller
180 and a display panel 150. The timing controller 180 includes a
gray scale curve amending module 110, a frame memory 120, two
luminance query tables 130 and 140, and a signal generator 160. The
display panel 150 is electrically connected to the luminance query
tables 130, 140, and the signal generator 160. The gray scale curve
amending module 110 is electrically connected to the frame memory
120, the luminance query tables 130. The frame memory 120 is
electrically connected to the luminance query table 140.
[0025] The timing controller 180 receives and processes frame image
data as a frame unit, and provides two corresponding sub-frames
Fn+1_1 and Fn+1_2 image data to the display 150. The display panel
150 receives the two sub-frames Fn+1_1 and Fn+1_2 image data to
generate corresponding images. The signal generator 160 generates
and provides various control signals such as sync signals or data
enable signals, and transmits the control signals to the display
panel 150 to control the image timing of the display panel 150. The
frame memory 120 temporarily stores the frame data, such as the
frame F(n) shown in FIG. 3.
[0026] The gray scale curve amending module 110 processes and
amends gray scales of the sub-frames to generate corresponding
amended gray scales. When the average gray scales of the received
frame F(n+1) and the frame F(n) stored in the frame memory 120 are
not unequal to each other, the gray scale curve amending module 110
processes and amends the gray scales of the corresponding
sub-frames Fn+1_1 according to the average gray scales of the
frames F(n) and F(n+1) to generate corresponding amended gray scale
of the sub-frame Fn+1_1.
[0027] The luminance query table 130 controls the luminance of the
sub-frame Fn+1_1 according to the gray scales from the gray curve
amending module 110, and outputs a first sub-frame image data
included in the sub-frame Fn+1_1. The luminance query table 140
controls the luminance of the sub-frame Fn+1_2 according to the
gray scales of the received sub-frame F(n+1), and outputs a second
sub-frame image data included in the sub-frame Fn+1_2. A first
motion picture response function (namely, the first gamma curve
f1(g)) is stored in the luminance query table 130, so that the
luminance query table 130 includes all the gray scales of the
sub-frame Fn+1_1 to look up the luminance corresponding to the gray
scales. Similarly, a second motion picture response function
(namely, the second gamma curve f2(g)) is stored in the luminance
query table 140, so that the luminance query table 140 includes all
the gray scales of the sub-frame Fn+1_2 to look up the luminance
corresponding to the gray scales.
[0028] Referring to FIGS. 3, 4, and 5, FIG. 4 shows different gray
scales corresponding to multiple consecutive frames F(n-1), F(n),
F(n+1), F(n+2), and F(n+3) when the gray scale curve is not amended
by the gray scale curve amending module 110 and frame memory 120.
FIG. 5 shows different gray scales corresponding to multiple
consecutive F(n-1), F(n), F(n+1), F(n+2), and F(n+3) when the gray
scale curve is amended by the gray scale curve amending module 110
and frame memory 120. In detail, each frame as shown in FIGS. 4 and
5 corresponds to two consecutive sub-frames showed in FIGS. 1 and
2. For example, when the timing controller 180 displays frame
F(n+1), the frame F(n+1) includes and displays two consecutive
sub-frames Fn+1_1 and Fn+1_2, the sub-frames Fn+1_1 corresponds to
the first gamma curve f1(g), and the sub-frames Fn+1_2 corresponds
to the second gamma curve f2(g) shown in FIG. 2.
[0029] In FIG. 4, assuming that the timing controller 180 receives
the successive frames F(n-1), F(n), F(n+1), F(n+2), and F(n+3), the
corresponding gray scales of the frames F(n-1), F(n), F(n+1),
F(n+2), and F(n+3) are 160, 160, 64, 64, and 64. That is an average
gray scale of the frames is reduced from 160 to 64. When the frame
F(n) and the frame F(n+1) are continuously output from the timing
controller 180, the corresponding average gray scale of the frame
F(n+1) is raised to 190 from 160, and then reduced from 190 to 64,
resulting in generating a larger slope on an average gray scale
curve shown on FIG. 4. When the average gray scale is transiently
raised to 190 from 160, the luminance of the display images on the
display panel 150 is accordingly increased, causing contour shadow
of the images. The contour shadow is a kind of a circle of bright
track or a layer of dark track. When the display panel 150 displays
high-brightness images, the bright track is formed around the
bright image due to a sudden increase of the image brightness. When
the display panel 150 displays low-brightness images, the dark
track is formed outside the dark images due to a sudden reduction
of the image brightness.
[0030] The gray scale curve amending module 110 and the frame
memory 120 are used to amend the gray scale curve. When the gray
scale of frame F(n+1) is less than the gray scale of the
previously-received frame F(n), the gray scale curve amending
module 110 processes and amends the gray scale of frame F(n+1), and
provides a gray scale which is less than the gray scale of frame
F(n+1). When the gray scale of frame F(n+1) is greater than the
gray scale of frame F(n), the gray scale curve amending module 110
processes and amends the gray scale of frame F(n+1), and provides a
gray scale which is greater than the gray scale of frame
F(n+1).
[0031] Referring to FIG. 5, for example, in this exemplary
embodiment, the gray scale of frame F(n+1) is 64, and the gray
scale of frame F(n) is 160. In order to avoid contour shadow, the
gray scale curve amending module 110 amends the gray scale of
sub-frame Fn+1_1, reduces the gray scale from 190 to 174, and
reduces the gray scale of frame F(n+1) from 64 to 48 as shown in
FIG. 4. In other words, the gray scale change interval of sub-frame
Fn+1_2 is changed from 190-64 to 174-48, so that contour shadow is
further eliminated on the display panel 150. The gray scale
difference 14 between 160 and 174 can be set as a critical gray
scale difference. In addition, the critical gray scale difference
is generated according to the gray scale difference 96 between the
average gray scale 160 of frame F(n) and the average gray scale 64
of frame F(n+1).
[0032] FIG. 6 shows different gray scales corresponding to multiple
consecutive frames F(n-1), F(n), F(n+1), F(n+2), and F(n+3) when
the gray scale curve is not amended by the gray scale curve
amending module 110 and frame memory 120. Among them, the average
gray scale of frames F(n) is increased to the average gray scale of
F(n+1). Then assuming that the timing controller 180 receives the
successive frames F(n), F(n+1), F(n+2), and F(n+3), the
corresponding gray scales of the frames F(n-1), F(n), F(n+1),
F(n+2), and F(n+3) are 64, 64, 160, 160, and 160, respectively.
That is, the average gray scale of the frames is raised from 64 to
160. Thus, When the frame F(n) and the frame F(n+1) are
continuously output from the timing controller 180, the
corresponding average gray scale is raised from 64 to 160,
resulting in generating contour shadow on the display panel
150.
[0033] FIG. 7 shows different gray scales corresponding to multiple
consecutive F(n-1), F(n), F(n+1), F(n+2), and F(n+3) when the gray
scale curve is amended by the gray scale curve amending module 110
and frame memory 120. Among them, the average gray scale of frames
F(n) is raised to the average gray scale of frame F(n+1). Then, the
gray scale curve amending module 110 and the frame memory 120 are
used for amending the average gray scale curve to output
corresponding gray scales which are less or greater than the gray
scale of frame F(n+1) as shown in FIG. 5, resulting in the
avoidance of contour shadowing. The specific descriptions of FIGS.
6 and 7 respectively correspond to FIG. 4 and FIG. 5, so there is
no need for detail.
[0034] Furthermore, the sub-frame Fn+1_1 not only corresponds to
the first gamma curve f1(g) shown in FIG. 2, also can correspond to
the second gamma curve f2(g) in another exemplary embodiments.
Similarly, the sub-frame Fn+1_2 not only corresponds to the second
gamma curve f2(g) shown in FIG. 2, but also can correspond to the
first gamma curve f1(g) according to actual situation. In other
words, the timing controller 180 can control output to the
luminance of the frame F(n+1) according to the variation of the
gray scales, and both the outputting order of the two sub-frames
about the luminance lighting before dimming or dimming before
lighting can be used.
[0035] Referring to FIG. 8, a method for improving motion blur and
contour shadow of the display 100 in accordance with an exemplary
embodiment of the disclosure including at least the following steps
is depicted.
[0036] In step S302, each motion picture response function
corresponding to a gray scale is separated into a first motion
picture response function and a second motion picture response
function on the display panel 150. The display 100 displays a
plurality of frame images, each frame image includes a plurality of
gray scales, and each gray scale corresponds to one motion picture
response function.
[0037] In step S304, the first motion picture response function and
the second motion picture response function corresponding to gray
scales are stored in at least one luminance query table.
[0038] In step S306, a first average gray scale is used to display
a first frame, a second average gray scale is used to display a
second frame, so when the first average gray scale is unequal to
the second average gray scale, the second average gray scale is
accordingly transformed into a third average gray scale. Among
them, the third average gray scale is greater than the first
average gray scale and the second average gray scale, or less than
the first average gray scale and the second average gray scale.
[0039] In step S308, an amended luminance corresponding to the
second frame is generated according to the third average gray scale
and the luminance query tables.
[0040] In summary, while the display 100 displays a plurality of
frames, each gamma curve for controlling luminance of frames is
separated into gamma curve to display two corresponding sub-frames
having different luminance. Besides, the single frame and the
previously-received frame are adjusted with a related gray scale
curve so that motion blur and contour shadow may be eliminated
simultaneously while consecutively outputting two frames having
gray scales and having a significant difference with each
other.
[0041] It is to be understood, however, that even though numerous
characteristics and advantages of the exemplary disclosure have
been set forth in the foregoing description, together with details
of the structure and function of the exemplary disclosure, the
disclosure is illustrative only, and changes may be made in detail,
especially in matters of shape, size, and arrangement of parts
within the principles of exemplary disclosure to the full extent
indicated by the broad general meaning of the terms in which the
appended claims are expressed.
* * * * *